Ng W H, Moochhala S, Yeo T T, Ong P L, Ng P Y
National Neuroscience Institute, Singapore.
Neurosurgery. 2001 Sep;49(3):622-6; discussion 626-7. doi: 10.1097/00006123-200109000-00016.
Nitric oxide (NO) plays an important role in the pathogenesis of neuronal injury after brain ischemia, and decreased levels of NO have been implicated in the pathogenesis of vasospasm after subarachnoid hemorrhage (SAH). In this study, we measured the ventricular cerebrospinal fluid (CSF) NO levels in patients with SAH and correlated the levels with clinical grade and middle cerebral artery velocities measured with transcranial Doppler ultrasound.
All patients with spontaneous SAH documented on computed tomography and with an external ventricular drain inserted within 24 hours of hemorrhage were included in the study. A total of 16 patients were studied between August 1999 and August 2000. CSF was collected serially at the time of surgery and subsequently at daily intervals. It was collected during the time that the external ventricular drain remained patent and in situ. NO levels were measured by photometric analysis by using a nitrite/nitrate assay kit (Cayman Chemical, Ann Arbor, MI).
The peak NO level in patients with SAH ranged from 9.96 to 168.16 micromol, with a median of 36.93 micromol. The levels were significantly elevated as compared with the control group (5.16 micromol, P < 0.05). The median NO level in patients with poor-grade SAH was 67.14 micromol as compared with 27.42 micromol in patients with good-grade hemorrhage (P < 0.05). No correlation was seen between CSF NO levels and middle cerebral artery velocities. The median NO level was 33.2 micromol in patients with a poor outcome as compared with 30.25 micromol in patients with a good outcome (P > 0.05).
This study showed that NO levels are elevated after spontaneous SAH, and the degree of elevation is higher in patients with poor-grade SAH.
一氧化氮（NO）在脑缺血后神经元损伤的发病机制中起重要作用，而NO水平降低与蛛网膜下腔出血（SAH）后血管痉挛的发病机制有关。在本研究中，我们测量了SAH患者脑室脑脊液（CSF）中的NO水平，并将这些水平与临床分级以及经颅多普勒超声测量的大脑中动脉速度进行关联。
本研究纳入了所有经计算机断层扫描证实为自发性SAH且在出血后24小时内插入外部脑室引流管的患者。1999年8月至2000年8月期间共研究了16例患者。在手术时及随后每天间隔收集CSF。收集时间为外部脑室引流管保持通畅且在位期间。使用亚硝酸盐/硝酸盐检测试剂盒（开曼化学公司，安阿伯，密歇根州）通过光度分析测量NO水平。
SAH患者的NO水平峰值范围为9.96至168.16微摩尔，中位数为36.93微摩尔。与对照组（5.16微摩尔）相比，这些水平显著升高（P < 0.05）。SAH分级差的患者中NO水平中位数为67.14微摩尔，而分级好的出血患者为27.42微摩尔（P < 0.05）。CSF中NO水平与大脑中动脉速度之间未发现相关性。预后差的患者中NO水平中位数为33.2微摩尔，而预后好的患者为30.25微摩尔（P > 0.05）。
本研究表明自发性SAH后NO水平升高，且SAH分级差的患者升高程度更高。
